Motor controller



April 1 1924. 1,488,934

N. L. MORTENSEN MOTOR CONTROLLER,

Filed June- 21, 1917 Patented Apr. 1, 1924.

UNITED STATES PATENT OFFICE.

NIELS L. MORTENSEN, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER-HAM- MER MFG. 00., OF MILWAUKEE, WISCONSIN, A CORPDRATTON OF WISCONSIN.

MOTOR CONTROLLER.

Application filed June 21, 1917. Serial No. 176,033.

To all whom it may 007?.067'7t.

ie it known that I, NIELS L. MoRrnNsnN, a subject or the King of Denmark, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Motor Controllers, out which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

This invention relates to motor controllers and more particularly to reversing controllers having GlGOllilO-I'QSPOllSlVQ accelerating or speed regulating switches provided with shunt windings.

In practice, considerable diiliculty has been experienced with such controllers due to the tendency of: the shunt windings to operate the accelerating or speed regulating switches prematurely upon quick reversals or the controlled motors, and the present invention has among its objects to provide a controller which will obviate such difficulty.

A further object is to provide a controller wherein the shunt winding or windings of the aforesaid switch or switches will be subjected to control by the motor during the periods of reversal thereof to insure against premature operation of said switch or switches.

Other objects and advantages will hereinafter appear.

The accompanying drawing illustrates diagrammatically one embodiment of the invention wherein shunt windings are em ployed for an accelerating switch and 3. held regulating switch and the same will now be described.

Referring to the drawing, the same shows a reversible compound motor 1 having an arn'iature a, a series field winding 7 and a shunt field winding f, said motor to be controlled through the medium of starting resistances r, 1- and r and a shunt field resistance 7'.

The controller illustrated comprises a contact drum 2 to reverse the flow of current through the motor armature a, electro-responsive accelerating switches 3, l and 5 to control the resistances r, r and 7' respec tively and an electro-responsive field regulating switch 6 to control the resistance r Each of the accelerating switches is of the so-called lockout type having an operating winding 7 and a lookout winding 8 connected in series with one another and in series with the motor armature whereby each switch operates in a well known manner to exclude its respective resistance subject to control by the current value of the motor circuit. Also, the accelerating switches are interconnected whereby the inclusion in circuit oi the windings of switch 4 requires prior closure of switch 3 and inclusion in circuit of the windings of switch 5 requires prior closure of switch 4:. Further, the cir-' cuit arrangement is such that switch 5 in closing short-circuits switches 3 and 4, together with the operating and lockout windings of all three switches and said switch 5 is provided with a shunt winding 9 for holding the same in closed position.

he iield regulating switch 6, which is normally closed to short circuit field resistance W, is provided with a single shunt 0pcrating winding which, as will appear, is connected in parallel with the holding winding 9 of accelerating switch 5.

The contact drum 2 has contacts 10 00-01)- erating in neutral position of said drum to establish a dynamic braking circuit for the motor armature, contacts 11 and 11 tocomplots the motor circuit for operation of the motor in one direction and contacts 12 for completing the motor circuit for reverse op eration. Also, the contact drum is provided with co-operating contacts 13 to complete the circuits of the winding of field regulating switch 6 and the holdingwinding of accelerating switch 5 when said drum is moved to either running position and to interrupt the circuit of said windings when said drum is returned to neutral position.

Upon movement of the contact drum to either running position the switches 3, 4 and 5 are rendered responsive to exclude the starting resistances r, r and r progressively for automatic acceleration of the motor. Also, the field regulating switch 6 is rendered responsive to include the field resistance 1" but the response of said switch is delayed by the connections now to be described until after removal of all of the starting resistance.

The winding of switch 6 and the parallel holding winding 9 of switch 5 are connected 011 one side to starting resistance 1" at an intermediate point and thence through a portion of said resistance and resistance r to one of the supply lines, while said windings are connected on the other side thereof through contacts 13 of the drum to the other supply line.

Accordingly, switch 6 it will as upon initial starting; or the motor connected in shunt with the motor ar are, series field, startin resistance a port-ion of starting resistance 1', wherein the current through said nindi i 'tional to the inoreoier, is

motor current.

Cling UElii said startin resistance (1 red t the current th Winding is not appreciably rec through the Si arting The i switch 6 last 'l e conditions. on; ore, is designed 1 osingthe switch oil it I at the meme connections t "ii vI T1 e couiiter 33. Ed. in.

Yoltag'e the mo added to the line voltage, thus suiie g once to the sum of t to i if said res" stance he reg-arsed as diviued in two sections, the value oi one section beingproportional to the line Voltage anti the value of th other section being; noportiona vl F oi the motor, the

to the counter is. potentinl at the 'erinediate point Where LlOllS unite will equal the potential 1e motor is connected said at the point where tl to the line.

Upon increment from one running position, the COllllQL' ture to he i circuit oi t t of said oint c same to he connected l in :lCCGllltlilCt with ordinm tiTe-l c high a'cltug shunt windings of the switches he seine hsj-ie been afforded time to open and close resgectifly in response to the previous circuit interruption. thus tendto cause said switches to act premat irely.

But with one side of said shunt windings connected between side drop in pot the moment or sponse oi Stiltl its the used until, in

. iii

' UL i Q l I 's to he node 4 id ti connei': 1 ii the Windiz; z. is .in' that i to exclude reircuit w ieh ihen -osin \rimling T of wed" through said u ces i" and 1' as inst traced erves in hire manner to (V- enere'ize the cl switch g. Ivy conduct r :23, while i of switch 110 5 e Windpwludes inc-s oi. all

cult, which therez= '3 motor cir- "oin cenduo conductor ncuctors lielt znence h conductor nial y closed sW' "ell 5 and iii conductor said circuit.

he encrglzi from ctniductor j v conductor 31. through 1 drain contacts and h conductor 32 1t 101, H 3 W1 1 '1 s i 4.1 L .iousn his Minding oi mic snitch, L-lQllCe by conductor 33 to the in ern ediste tap 34 in resistance 'r.

The circuit of holding coil 9 extends to conductor 32 as ast traced,.thence by con ductor through said coil and by conductor 36 to the tap 34.

What I claim as new and desire to secure by Letters l e/tent is:

1. In con'ihinaticn, an electric motor, a supply circuit therefor, plugging means for said motor, a series resistance for said motor and electro responsive switches for progressively excluding portions of said resistance each of said switches having a series winding to close the same and one of said switches having a shunt winding to hold the same in closed position, said latter winding being connected to the motor circuit throughout the plugging periodat points which as the result oi the plugging action are of reduced potential difference.

2. In combination, an electric motor having shunt lield, a supply circuit and plugging means for motor, a series resistance for said motor, a field resistance and an electro-responsive switch for controlling said field resistance, said switch having a shuntcontrol winding connected to the motor circuit throughmit the plugging period at points which as the result oi the plugging action are of reduced potential difference.

In combination, an electric motor having a shuntfield, a supply circuit and plugging means for said motor, a series resistance for said motor, a hold resistance and electro-responsive switches or excluding said resistances, said sw gches having shunt windings arranged in parallel with eaci other and connected to the motor circuit throughout the plugging period at points which as the result of the plugging action are of reduced potential difference.

l. In combination, an electric motor, a. supply circuit therefor, reversing means for said motor, a series resistance for said motor and an electro-responsive switch for excluding said resistance, said switch having series and shunt windings to respectively close and hold the same, said latter winding being connected on one side to said supply circuit and on its other side to said resistance at an intermediate point.

5. In combination, an electric motor having a shunt field, a supply circuit and reversing means for said motor, a series resistance for said motor, a field resistance and an electro-responsive switch for controlling said field resistance, said switch having a shunt control winding connected on one side to said supply circuit and on its other side to said series resistance at an intermediate point.

In con'ihination, an electric motor having a shunt held, a supply circuit and resaid versing means for said motor, a series resistance for said motor, a field resistance and electro-responsive switches for excluding said resistances, said switches having shunt windings arranged in parallel with each other and connected on one side to said supply circuit and on their opposite sides to said series resistance at an intermediate point. i

7. In combination, an electric motor hava shunt held, a supply circuit and reversing means for said motor, a series resistance and a field resistance for said Inotor, and electro-responsivc switches for governing the inclusion and exclusion of said resistances, said series resistance switch having series operating winding and a shunt holding windi g, said field resistance switch having ashunt operating winding, the shunt windings of switches being connected on one side thereof to said supply circuit and on their opposite sides to said series resistance at an intermediate point.

8. In combination, an electric motor, a supply circuit therefor, reversing means for said motor, a series resistance for said motor and an electric-responsive control switch for said motor having. a shunt control winding connected on one side to said supply circuit and on its other side to said resistance at an intermediate point, said switch when fully opened being unresponsive to said shunt winding. I

9. In combination, an electric motor, a supply circuit therefor, reversing means for said motor, a series resistance for said mtor and an electro-responsive switch for excluding said resistance, said switch having a shunt control winding connected on one side to said supply circuit and on its other side to said resistance at an intermediate point, said switch having means functioning when the same is fully opened to insure against closure thereof by said shunt winding.

10. In combination, an electric motor, a supply circuit therefor, reversing means for said motor, a series resistance for said motor and an electro-responsive switch for excluding said resistance, said switch having series and shunt windings to respectively operate and hold the same, said latter winding being connected on one side to said sup ply circuit and on its other side to said resistance at an intermediate point, certain of said windings being adapted when said switch is fully open to insure against closure thereof by said shunt winding.

In witness whereof, I have hereunto subscribed my name.

NIELS L. MORTENSEN. 

